I think you might be giving to much credit to the ki 84, it is going to be a good plane no doubt, but not anymore uber than than the uber rides the dweabs live in in the MA, the Spit's la-7's and ect's will have good company with the ki 84 it's guns are good but they will be the same ones we have on the Tony and with about the same ammo load, they are good gun's but the ammo goes very fast and you nead to be fairly close to get good hit's with the 20mm Ho-5's and 12.7mm Ho-103's. Preformance wise it will be i suspect a bit slugish like the George is, it has the same engine as the George so I would not expect it to be over Uber, P51's will still Zoom and boom and Run away just like they always do.
Adding the Nate and the oscar would be imo a bit waste of time, bad guns and weak airframes would not endear them to anyone and they would be hanger queans, why fly an oscar when you could take a Zero with 20mm Cannon's and actualy get a kill.
The Best thing about the D4Y is that it spans the whole war and has a great preformance for it's type, picking a good mid or late war model would be nice to set it aganst the TBM or SBD we have in AH at present.
Whats realy Scary is that the Ta 152 was actualy voted into the game, the Players picked it in a vote from several potential perk candates, including the tempest.
as to why not get both ya I gues if your going to dream go all the way right:), realistical even the 4 i sugested most likely will Not be added anythime soon, I was trying to be realisticly opmastic:)
Most all Late war japanese aircraft featured some armor protection, and genearly much more robast airframe construction than their early war predisasors, and some sort of self sealing fuel tank technolagy, the Jill had partial tank protection acording to my sorces.
Well us Ct types would like to see a more fleased out plane set for obvious reasion's and the Ki 44 being an entierly new plane would add to the develpoment length and theirfore be more taxing to HTC to do than an early Ki 61. Also the Ki 44 is not a good a mount as the Ki 84 and they were in service during roughly the same time.